The raw sewage discharged from humans is typically discharged into a sewage system by a flush toilet or the like and then flows into a river after purification in a holding tank. However, at events such as festivals, athletic events, fairs, meetings and the like, temporary toilet facilities must be provided for disposal of raw human waste.
Employed conventionally are movable temporary toilets, most of which have a tank for temporarily containing the raw sewage therein. However, temporary toilets require the raw sewage contained in the tank be sucked into a vacuum truck, and the collected raw sewage must then be transferred to a sewage purifying facility. This is laborious and time consuming and is unhygienic.
Transportation vehicles such as trains and buses, which operate over long distance, are provided with a tank exclusively for storing the discharged raw sewage. The raw sewage in this tank is subjected to a chemical deodorizing treatment and is thereafter collected by a vacuum truck at a terminal or collection point.
The storing, collecting and disposal methods are thus not modern and are very unhygienic. If the temporary toilet has been used for a long period of time, the raw sewage in the tank causes a bad smell, and operators dislike disposing of the raw sewage.
In an attempt to ameliorate the above problem, there have been proposed several hygienic disposal methods. In one method, chemicals are introduced into the raw sewage storage tank to prevent the generation of the bad smell and to effect sterilization of the sewage. This method, however, cannot be used for a long period of time because the chemicals become diluted, water flows in a stool is polluted with raw sewage, and costs are high, though this method is often employed in transportation vehicles.
In another method, the raw sewage is contained in a bag made of vinyl or the like to prevent the diffusion of the bad smell. This method, however, requires a vinyl bag of large size and involves a high cost for disposal thereof, and it is troublesome to separate the raw sewage from the bag. A large-scale disposal facility is also required.
In view of the drawbacks of the conventional method of disposing of raw sewage as discussed above, the present inventor proposed a disposing apparatus having the drying cauldron provided with stirring blades and heat-holding balls therein in which the raw sewage is stirred by the rotation of the stirring blades and heated by heat released by the heat-holding balls whereby the raw sewage is dried in a short period of time and the liquid component is evaporated. Arrangements of this general type are disclosed in Japanese Patent Nos. 63-124150 and 2-411577, as well as U.S. Pat. Nos. 4,999,930, 5,058,213, 5,152,074, 5,230,164, 5,257,466, 5,261,126 and 5,418,982.
According to my proposed disposal methods, the raw sewage is heated, evaporated in the drying cauldron and diffused into the ambient atmosphere. Before the liquid component is diffused, the components which cause bad smell are resolved by a catalyst so that the liquid water is diffused into the atmosphere as an odorless vapor. It is preferable to employ such methods in view of environmental hygiene and preservation even if such methods are employed in crowded buildings and/or by throngs of people.
It is very hygienic to evaporate and diffuse the raw sewage contained in the airtight drying cauldron and such operations can be carried out systematically, which results in not causing a burden to the operators. It is necessary to stir the raw sewage which is contained in the airtight drying cauldron so as to heat and evaporate the raw sewage uniformly and residual substances which are not evaporated must be removed.
In the arrangement provided with a stirring blade, it is necessary to provide a rotary shaft which extends perpendicular relative to the drying cauldron, which entails increasing the height of the apparatus as a whole and which makes the mechanism very large. There is a case that foreign matter which cannot be evaporated, such as a metallic ball-point pen, a belt, clothing, etc. are introduced into the drying cauldron. In such a case, when the raw sewage is stirred the foreign matter enters a gap between the stirring blade and the drying cauldron, which prevents the stirring blade from rotating, and hence causes trouble. Since the rotary shaft and the stirring blade must be accommodated inside the drying cauldron, the limited inner space of the drying cauldron is occupied by these mechanisms. As a result, the inner space of the drying cauldron cannot be effectively utilized, which leads to inconveniences.
In an attempt to at least minimize these latter inconveniences, the inventor has made further improvement in such arrangement by eliminating the stirring blades, such modified arrangement being disclosed in Japanese Patent Application Serial No. 314445/93, and corresponding U.S. application Ser. No. 08/342 415. While this modification does represent an improvement, nevertheless there is still a desire to simplify the overall structure of the drying arrangement, and specifically the structure and mechanism for rotatably supporting the drying cauldron.
With this objection in mind, the present invention provides a raw sewage disposal apparatus having a drying arrangement which includes a cauldron into which the raw sewage is disposed and is subjected to heating, stirring and evaporation. The drying cauldron is horizontally rotatably supported by a simple mechanism which cooperates between the open upper end of the cauldron and a supporting frame so as to provide both a simple structure and a simplified operation. The advantageous arrangement of the present invention is explained in greater detail hereinafter.